Field of the Invention
The present invention relates to a control apparatus for an electrostatic type touch panel and a control method for the electrostatic type touch panel.
Description of the Related Art
In recent years, the number of information processing apparatuses provided with a touch panel as a user interface has been increased. The touch panel includes a resistance film type, an infra-red type, and an electrostatic capacitance type.
The touch panel of the electrostatic capacitance type is configured to determine whether or not the touch panel is touched on the basis of a change in an electrostatic capacitance. Specifically, a plurality of electrostatic sensor patterns made of indium tin oxide (ITO) or the like are arranged, and when an increase in the electrostatic capacitance of any one of the electrostatic sensor patterns as compared with a non-operation state is detected, it is determined that the touch panel is touched. According to Japanese Patent Laid-Open No. 2007-208682, an electrostatic capacitance value corresponding to a reference of the non-operation state is stored in advance, a change in the electrostatic capacitance is detected, and in a case where a variation thereof is higher than or equal to a previously set value, it is determined that the touch panel is touched by a finger or the like.
However, a temperature of a finger of a user who performs an operation may be higher than that of the touch panel in many cases. Therefore, when the finger of the user touches the touch panel for a long time or when the finger of the user touches the touch panel that has been placed in a low temperature environment, heat is conducted to the touch panel from the finger, and a dielectric constant of the electrostatic sensor may be changed. In this case, even when the finger is released from the touch panel, a difference exists from an electrostatic capacitance value in the non-operation state before the finger touches the touch panel, and it is determined that the touch panel is in an operation state, which leads to a problem that a malfunction occurs.